The gun, or "grown up notepad" is windows notepad rewritten in assembler for speed (so it does not chug up when you open a larger file). Its basically identical to notepad otherwise.
notepad ++ is not simple nor minimal but is great for coding and supports OLD visual studio style macros and alt-select (rectangle selection) and has code syntax hightlighting.
unix or unix on windows can use any of many, Ive been partial to nano under cygwin (windows) and unix for many years. Pico is similar.
I always loved pure windows 'edit' but I believe it has vanished from the OS and takes hax to get it back up and running in newer windows.